I've actually been spending some time on this, finally! I have the first half "under my fingers" as I like to say -- nothing remotely like performance ready, but it's making some sense, fingerings figured out, can eek through it slowly, haltingly, way under tempo ...
Curious: what are folks doing for dynamics? My version (from the collected works book) only has mp at the beginning, a crescendo leading up to the key change, then f from there on out. It seems like it wants a bit more than that, but I don't have anything systematic in mind, maybe just play it a little louder or softer here and there as I'm feeling it.
Also: the composer's notes say "Use the sustain pedal throughout to create a richness of sonority but avoid clashing harmonies." I honestly don't see how it's possible to play this without clashing harmonies, but I also don't think it's really a problem. So much of this sort of piano music is recorded with generous amounts of reverb, so the clashing just seems like part of the studio sound. Looking at performances online, it doesn't seem like anyone is all that bothered by it as they're playing, so I don't think I'll get too uptight about it either.